guarding against avx512vl operations

Author: DiamonDinoia

include/xsimd/arch/xsimd_avx2.hpp

@@ -200,10 +200,12 @@ namespace xsimd
             {
                 return _mm256_sllv_epi32(self, other);
             }
+#if XSIMD_WITH_AVX512VL
             else XSIMD_IF_CONSTEXPR(sizeof(T) == 8)
             {
                 return _mm256_sllv_epi64(self, other);
             }
+#endif
             else
             {
                 return bitwise_lshift(self, other, avx {});
@@ -343,10 +345,12 @@ namespace xsimd
                 {
                     return _mm256_srlv_epi32(self, other);
                 }
+#if XSIMD_WITH_AVX512VL
                 else XSIMD_IF_CONSTEXPR(sizeof(T) == 8)
                 {
                     return _mm256_srlv_epi64(self, other);
                 }
+#endif
                 else
                 {
                     return bitwise_rshift(self, other, avx {});

include/xsimd/config/xsimd_config.hpp

@@ -244,6 +244,17 @@
 #define XSIMD_WITH_AVX512DQ 0
 #endif
 
+/**
+ * @ingroup xsimd_config_macro
+ *
+ * Set to 1 if AVX512VL is available at compile-time, to 0 otherwise.
+ */
+#ifdef __AVX512VL__
+#define XSIMD_WITH_AVX512VL XSIMD_WITH_AVX512F
+#else
+#define XSIMD_WITH_AVX512VL 0
+#endif
+
 /**
  * @ingroup xsimd_config_macro
  *